deque

Category: Collections
Wire type: deque
Construction: CREATE

Collections are synchronized mutable structures manipulated with OP.

Create a value

Use the top-level CREATE command to initialize this structured value. The example shows its construction options.

amaquet-cli -uri amaquet://127.0.0.1:13378 CREATE '{"key":"example:deque","type":"deque","options":{"capacity":8}}'

Construction options

Example CREATE options: {"capacity":8}. Omitted fields use server defaults.

Supported operations

PUSH_FRONT, PUSH_BACK, POP_FRONT, POP_BACK, VALUES, LEN.

See the complete operation contract for exact arguments, defaults, results, and whether a listed GET is the top-level key command or a type-specific OP. It also identifies read-only operations and documents validation, lazy maintenance, and key-version behavior.

Operation payloads

The following examples use the public amaquet-cli JSON command format. Replace example:deque with the key used by your application.

Construction payloads

Use the payload below to initialize this type before issuing reads or type-specific operations.

CREATE

This payload initializes the value and must complete before its type-specific operations are used.

{
  "key": "example:deque",
  "type": "deque",
  "options": {
    "capacity": 8
  }
}

Operations

Each request uses the OP envelope. The response is the type-specific value described in the complete operation contract.

OP PUSH_BACK

Accepts nested value and returns new length.

{
  "key": "example:deque",
  "operation": "PUSH_BACK",
  "args": {
    "value": {
      "type": "utf8_string",
      "value": "alpha"
    }
  }
}

OP PUSH_FRONT

Accepts nested value and returns new length.

{
  "key": "example:deque",
  "operation": "PUSH_FRONT",
  "args": {
    "value": {
      "type": "integer",
      "value": 7
    }
  }
}

OP LEN

Takes no arguments and returns logical-order values or length.

{
  "key": "example:deque",
  "operation": "LEN",
  "args": {}
}

OP POP_FRONT

Takes no arguments and returns the first typed value or null.

{
  "key": "example:deque",
  "operation": "POP_FRONT",
  "args": {}
}

OP POP_BACK

Takes no arguments and returns the last typed value or null.

{
  "key": "example:deque",
  "operation": "POP_BACK",
  "args": {}
}

OP VALUES

Takes no arguments and returns values in logical order.

{
  "key": "example:deque",
  "operation": "VALUES",
  "args": {}
}

Top-level read payload

GET reads the current value without changing it:

{
  "key": "example:deque"
}

Key lifecycle payloads

These commands apply to the key regardless of its registered type:

• TYPE: {"key":"example:deque"} — returns the wire type.
• EXISTS: {"key":"example:deque"} — reports whether the key exists.
• EXPIRE: {"key":"example:deque","ttl_ms":5000} — assigns a five-second TTL.
• TTL: {"key":"example:deque"} — returns the remaining TTL in milliseconds.
• PERSIST: {"key":"example:deque"} — removes the TTL.
• DEL: {"keys":["example:deque"]} — deletes the key.

For defaults, validation, result shapes, and persistence classification, see the complete operation contract.

Key lifecycle

The key participates in TYPE, EXISTS, TTL, EXPIRE, PERSIST, and DEL. Top-level GET returns the type’s direct public value or a synchronized snapshot.